Hubble telescope confirms the existence of dark energy.

When NASA's Opportunity rover dug a trench into the Martian soil two days ago, it revealed a series of mysteries that scientists back on Earth are still puzzling out. The tiny spherical granules that Opportunity found on the surface with its microscope are also underneath the topsoil, but strangely, these look shiny and polished. Opportunity's next task will be to examine a region of exposed rock which has many of these granules embedded inside to help give scientists a better idea of what they're looking at.

The Hubble Space Telescope has further confirmed the existence of "Dark Energy" - a mysterious force that seems to be accelerating the expansion of the Universe. The giant space observatory examined some of the most distant supernovae ever seen and found that this force seems to have been acting at a constant rate for as far back as Astronomers can see. This is good news. If Dark energy continued to accelerate, some physicists believe the fabric of the universe could tear apart in an event called "The Big Rip".

Jupiter's Moon Io is depositing a trail of dust particles as it makes its journey around the Sun, and the European Space Agency's Ulysses spacecraft has detected them 500 million km away from the gas giant. The dust streams contain particles no larger than smoke, and they originate from Io's many volcanoes, which are constantly erupting across its surface. One unusual feature about the streams is that they have a period of 28 days, which suggests they somehow interact with the solar wind streaming from the Sun.

Instead of looking directly for Earth-sized planets, it might be easier to just try to find the ring of dust that is the fingerprint of Terrestrial planet formation. This is according to a new computer model created by Astronomers from the Smithsonian Center and Astrophysics and the University of Utah. Their model predicts that stars with disks will be a little brighter in the Infrared spectrum than stars without disks; Astronomers should be able to predict the size of its planets just from the brightness of its disk in infrared. The recently-launched Spitzer space telescope should be the perfect tool to measure these disks.

Astronomers from Caltech and Yale University have discovered a distant object that could be nearly as large as Pluto. The planetoid is called 2004 DW, and located in the Kuiper Belt, billions of kilometres from Earth. The team estimates that 2004 DW is 1,400 km across, but it's difficult to tell, because the size estimate comes from its brightness. The reflected light from the Sun, which Astronomers call "albedo", depends on the darkness of the object. Other Astronomers will try and help pin down the characteristics of 2004 DW.